80's Technics Integrated Amps

Have this coming from JAPAN

An X90 system... ST-X70T (this one has TV band)
SU-X90 (black push buttons instead of silver)
RS-X90WR - double cassette - not had this model before.

IMG_0166.JPG
 
Love the V4X amps...

What speakers you run?

Your posts were one of the reasons, why I was specifically looking for this model :)
Regarding speakers, I'm on a search now, do you have some suggestion? Something that would pass to this amp and doesn't cost thousends? :)
Cheers
 
Technics SB-6 SBX-700 I'm running ATM on 2 of my V4X systems ATM.. V4X amps bring out the best of any spkrs I've heard... I reckon just listen to a few and decide on what you like
 
Technics SB-6 SBX-700 I'm running ATM on 2 of my V4X systems ATM.. V4X amps bring out the best of any spkrs I've heard... I reckon just listen to a few and decide on what you like
Hi,
do you consider an sb-4 rather too weak and small for an SU-V4X? Waht do you think?
 
Should still sound great... but the V4X will be too big to push to capacity.... but you probably wouldn't have to do that... at a normal level, they should sound smooth with a nice clean depth.

Positioning of speakers will have the biggest impact... I have a V4X on some SB X300A speakers which is in the same bracket as SB 4 speakers And they really sound bigger than I'd have thought... very deep clean sound

If you like to often use higher volume maybe look into the bigger brothers SB 6 or SB 8...
 
Hi guys 'n gals... been visiting this site more and more lately and decided that I'd better join the group.

I've owned a bunch of Technics audio components that I had bought in the early-mid '80's whilst I was stationed in Germany.
Started off with a SU-V4 amp with the peak-hold power meter display and RS-M240X Cassette, followed by a pair of Klipsch Heresy's, SL-QL1 Turntable. I also picked up an SH-8065 Equalizer, ST-G7 Tuner and the SL-PS900 CD player when they came out. All in all, been quite happy with these purchases, which have served me well pretty much the entire time of ownership. All components are original and in great, un-molested condition (except that the SH-8065 has a broken off pot slider, the pot still works fine).

I love the sound of the amp driving my Heresy's (I know, they don't have a deep, booming bass but that's OK by me) and they can reach quite insane loudness levels when I crank it up. I spend most of my listening time using the CD / turntable and cassette unit, with the tuner coming in dead last (don't much care for the music & ads they play around here).

Unfortunately, the amp (SU-V4) has been giving me grief as of late though. I've cleaned the pots a couple of times in the last 10 years. Think it may be time to do it again, but am worried that it's a bit more than that this time around.

Volume drops off to almost nothing one one of the two channels (not always the same one). The volume appears to be higher on the right side, so the balance has been staying just a bit off-center to compensate. I have been turning the volume up-down while the unit is turned off. I have found that the 'dropped' channel side comes back when I give the poor amp "a sharp slap between the ears" - i.e.- hit the cabinet simultaneously left/right on the sides with a slapping motion. Things get back to normal real quick. LOL.
Don't think it's good for it long term though. I'm thinking that it must be a loose wire/component somewhere, or a poor solder joint. If I remember correctly, there appears to be quite a lot of wire-wrap inside, without solder. I also bought a set of the STK8050 's out of GB a few years back, just in case. Hope that those are originals as stated, and not the knockoffs.

Hoping that some of you 'experts' on here can shed some light on this for me. I'm not an electronics expert, but have 'dabbled' a bit as I'm a trained Metrologist and spent 13yrs working for the military in an electro-mechanical laboratory calibrating and maintaining various forms of test equipment etc.

Matt
 
Last edited:
The fact you slap it to make it come good is screaming dry joint.... using a plastic stick, tap gently around various pcbs to see if you can localise the fault.
These amps also go bad with input selector and rec selector switch... t/here could go with a good clean (the amps of this era that I have I’ve cleaned the input selector switch, as these can certainly cause channel difference) switches on these are on input pcb on rear, controlled via steel cable slides.

Would in your case definitely be a good idea to go over the soldering... also check relay... pitted contacts can cause issues too

When soldering do make sure no solder runs to another joint causing a short... seen ppl bring amps in for the chaos caused by that...

Nice Avi btw :thumbsup:
 
Thanks. Will have to open it up in the next days, as time permits.
What do you think of the wire wrapped components- should I spray clean (or wipe with alcohol), then solder ; or just leave them as is?

The speaker protection relay beside D602 // R609?

Are there a lot of bogus STK8050 's floating around, or are these relatively 'safe'?

thx
 
Last edited:
I’ve never had trouble with the wire wrapped posts.... there’s only 1 Relay in the amp... protect relay that connects spkrs to output

Dry joints will certainly be playing a role.... a powerful magnifier makes them easier to see, though some are highly elusive...

Deoxit or equivalent for input selectors and tone/filter/loudness switches and tone/bal/vol pots

Once all dry joints and switches/pots are clean it would be time to check dc offset and bias to ensure all is at optimum

Service manual should be on hifi engine for procedures on setting bias etc
 
Hello, I have often read some of the forum posts over the years, today I have joined the forum as I am close to makeing a decision on changing my technics amp for another technics amp.
I have used and enjoyed for many years the monster Technics SU VX820 I know this is a good amp because I love the sound and have kept it many years, one of the experts has mentioned on here that it’s one of the good amps, I am sure I read that?!
However the left speaker has gone funny in the amp, it seems to work perfect in power amp direct feature but that’s the only way I can use it! I would like to play records also!
I always wanted a remote feature for volume too. maybe a gimic or not I love the gauges on an amp!
Anyway I am considering buying a pre and power amp set up, the SE-A1000 mk2 and
SU-C1000 mk2
I have found second hand for around £600
the above pre and power amps, are these true Technics? Will they sound similar, better or worse than the SU-VX820?
Really would appreciate expert opinions here,
And incase wondering I have tried many new amps from £700-£3000
Only the dearest amp setup of new amps came close and I could not justify the cost, to sound about the same!
for a lot more money I have also seen the Technics Pre and Power SE-A2000 & SU-C2000 are these worth buying? 2k+?
Robert.
 
Last edited:
It may be the power amp direct switch, or input selector switch causing issues with the channel.... a dry joint may too be the culprit

The A1000 would be a a step down from the older VX820

However the A2000 would be a good way to go...(dual Mono etc)

The A1000 is mos class AA with RSN6000 mos voltage amp and BC module SVI3205C current drive

See pic

9E479DE5-F432-4C89-9BF4-4F9B215D7FF2.jpeg

And the A2000 - you can see the supply array is somewhat on the next level

15E54B78-79E6-444D-BFA7-3BA922255F7B.jpeg
 
Thank you for a swift reply? You have saved me from rushing into wrong purchase.
Maybe I can fix my amp but, I would like remote control to turn volume up and down as a feature and the gauges with lighting if I am honest would be desirable to look at!

Is the A2000 better than my current amp?
I see it has remote control option
Is it worth £2.4k Pre and power in mint condition.

https://www.ebay.co.uk/itm/263383067687

Are there any others you would recommend I look at? similar to mine in build and quality with remote option?
 
Yeah, the A2000 has more power (akin to the VX800) as it’s 2 pair outputs per channel

The S/N ratio is better distortion lower and freq response is wider.

This should transform into a more cleaner sound with more capability

As for cost It’s a tough call... buy it once n you have it for a long time... id try to come in at 2K quid... they’re not so easy to find when you want them, and the one you’re looking at has correct voltage which is a good thing

But for you I’d suggest it over the A1000
 
Not sure how you can tell from the photo?
On the subject of voltage though I notice there is only the one for sale here in the UK, I think it’s to expensive myself! if I look in Europe there are many more for sale all around £1000 plus cheaper if I take today’s exchange rate into consideration.
if I took the decision to buy one from Germany or Portugal would it be a difficault job to get it working on uk 240?
Any questions I should ask above the
condition and all working,
packing extremely well, handle with care stamped in both laugages on the Box.
I can have delivered for £50 on a 3-4 day
 
Back
Top Bottom